IL-10 is a robust anti-inflammatory and immunosuppressive cytokine protein produced and secreted by many immune cells, including monocytes, macrophages, regulatory T cells, and T helper type 2 cells.68 IL-10 plays a role in dampening inflammatory responses by reducing antigen presentation and inhibiting the release of pro-inflammatory cytokines.69 Lower circulating and intestinal mucosal levels of IL-10 are associated with IBS,70–72 so IL-10 has become a target for upregulation in IBS. Here, IL10 is linked to irritable bowel syndrome.